package com.hmdp.service.impl;

import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.SneakyThrows;
import com.hmdp.config.RedissonConfig;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static{
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
    private static ExecutorService seckill_order_executor = Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init(){
        seckill_order_executor.submit(new VoucherOrderHandler());
    }
    private class VoucherOrderHandler implements Runnable{
        @SneakyThrows
        @Override
        public void run() {
            while(true){
                try {
                    //1.获取队列中的订单信息
                    VoucherOrder voucherOrder = orderTasks.take();
                    //2.创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (InterruptedException e) {
                    log.debug("处理订单异常"+e);
                }
            }

        }
    }
    public Result seckillVoucher(Long voucherId) {

        //1.执行Lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                UserHolder.getUser().getId().toString()
        );
        int r = result.intValue();
        if(r != 0){ //2.判断结果是否为0,不为0,代表没有购买资格
            return Result.fail(r==1 ? "库存不足":"不能重复下单");
        }
        //2.2.为0,有购买资格,把下单信息保存到阻塞队列
        long orderId = redisIdWorker.nextId("order");
        //封装
        VoucherOrder voucherOrder = new VoucherOrder();
        voucherOrder.setId(orderId);//订单id
        voucherOrder.setUserId(UserHolder.getUser().getId());//用户id
        voucherOrder.setVoucherId(voucherId);//代金券id
        //保存阻塞队列
        orderTasks.add(voucherOrder);
        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //3.返回订单id
        return Result.ok(orderId);
    }
    public IVoucherOrderService proxy ;
    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //1.获取用户
        Long userId = voucherOrder.getUserId();
        //2.创建锁对象
        RLock lock = redissonClient.getLock("lock:order:"+userId);
        //3.获取锁
        boolean isLock = lock.tryLock();
        //4.判断是否获取锁成功
        if(!isLock) {
            log.error("不允许重复下单");
            return;
        }
        try {
            //获取代理对象
            proxy.createVoucherOrder(voucherOrder);
        }finally {
            lock.unlock();
        }
    }

   /* @Override
    public Result seckillVoucher(Long voucherId) {
        //1.查询优惠券信息
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2.判断秒杀是否开始
        //2.1秒杀尚未开始返回异常
        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
            return Result.fail("秒杀尚未开始");
        }
        //2.2秒杀已结束返回异常
        if(voucher.getEndTime().isBefore(LocalDateTime.now())){
            return Result.fail("秒杀已经结束");
        }
        //3.判断库存是否充足
        if(voucher.getStock()<1){
            //3.1库存不足返回异常
            return Result.fail("库存不足！");
        }
        Long userId = UserHolder.getUser().getId();
        SimpleRedisLock lock = new SimpleRedisLock("order:"+userId,stringRedisTemplate);
        boolean isLock = lock.tryLock(1200);
        //判断是否获取锁成功
        if(!isLock) {
            return Result.fail("不允许重复下单");
        }
        try {
            //获取代理对象
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }finally {
            lock.unlock();
        }




    }*/
    @Transactional
    @Override
    public void createVoucherOrder(VoucherOrder voucherOrder) {
//6.一人一单
        Long userId = voucherOrder.getUserId();
        //6.1查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //6.2判断是否存在
        if(count>0){
            //用户已经购买过了
            log.error("用户已经购买过一次！");
            return;
        }
        //3.2库存充足扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1") //相当于set条件 set stock = stock - 1
                .eq("voucher_id", voucherOrder.getVoucherId()) //相当于where条件 where id = ? and stock = ?
                .gt("stock",0).update();
        if(!success){
            log.error("库存不足!");
            return;
        }

        long orderId = redisIdWorker.nextId("order");//订单id
        voucherOrder.setId(orderId);
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherOrder.getVoucherId());//代金券id
        save(voucherOrder);


    }
}
